Nonlinear molecular based modeling of the flash point for application in inherently safer design

New chemical process design strategies utilizing computer-aided molecular design (CAMD) can provide significant improvements in process safety by designing chemicals with required target properties and the substitution of safer chemicals. An important aspect of this methodology concerns the prediction of properties given the molecular structure. This study utilizes one such emerging method for prediction of a hazardous property, flash point (FP), which is in the center of attention in safety studies. Using such a reliable data set comprising 1651 organic and inorganic chemicals, from 79 diverse material classes, and robust dynamic binary particle swarm optimization for the feature selection step resulted in the most efficient molecular features of the FP investigations. Apart from the simple yet precise five-parameter multivariate model, the FP nonlinear behavior was thoroughly investigated by a novel hybrid of particle swarm optimization and support vector regression. Besides, 195 missing experimental FPs of the DIPPR data set are predicted via the presented procedure.     

CoFe2O4@Methylcelloluse as a New Magnetic Nano Biocomposite for Sonocatalytic Degradation of Reactive Blue 19

Journal of Polymers and the Environment - Reactive Blue 19 (RB19) removal from synthetic textile wastewater was investigated by using a CoFe2O4@methylcellulose (MC) activated with peroxymonosulfate...     

ANALYSIS OF ROCK STRESS AROUND A LIQUID WASTE INJECTION SYSTEM IN ILLINOIS1

: The danger to the environment associated with the injection of liquid industrial wastes into a deep, confined, subsurface rock formation may arise from the transport of the waste laterally or vertically in the formation. The pattern of lateral transport, which can take place as a result of convection as well as dispersion and diffusion, can be determined by an approximate analytical solution to the mass transport equation. Vertical transport may take place through both natural fractures and fractures created by hydrostatic stresses generated around the well during injection. To determine the stresses, we used the finite element method to get a numerical solution of the flow equation. We applied a solution of the flow equation to calculate the stress buildup and decay for the Jones & Laughlin Steel Corporation's injection well near Hennepin in Putnam County, Illinois. According to our computations, the stress buildup due to injection is about 0.16 pounds per square inch per foot - psi - (0.362 Newton per square centimeter per meter), which, added to normal pressure, makes an estimated total stress of 0.60 psi/ft (1.36 Newton/cm²/m). That pressure is insufficient to cause fracturing of the Cambrian Eau Claire aquitard, the confining bed for the disposal zone.     

Screening pesticides for their ability to damage bacterial DNA

Twenty-six pesticides and pesticide degradation products were screened (125 micrograms - 2000 micrograms) for their ability to induce unrepairable damage to bacterial DNA. Three repair test systems were utilized in this study, the Salmonella typhimurium (TA1538/TA1978), the E. coli K-12 (Pol A1+/Pol1-) and the E. coli WP2 (WP2, WP2uvrA, WP67, CM611 and CM571). Aldicarb (1000 micrograms), benomyl (250 micrograms), 2-aminobenzimidazole (2000 micrograms), captan (125 micrograms), fenazalor (500 micrograms), 5,6-dichloro-2-trifluoromethylbenzimidazole (NC-2983) (250 micrograms), isothymol (250 micrograms), maleic hydrazide (1000 micrograms), pentachloronitrobenzene (1000 micrograms) were DNA-damaging to one or more bacterial test systems. Isothymol and NC-2983 affected all three test systems. Chlorinated hydrocarbon insecticides, some being recognized as carcinogens, did not produce a zone of inhibition in any of the tester strains possibly due to their poor solubility and diffusion in the agar overlay. It was concluded that these tests can be performed along with bacterial reversion tests to complement each other as short-term screening tests for potential carcinogens and mutagens.     

Recycling soil nitrate nitrogen by amending agricultural lands with oily food waste

With current agricultural practices the amounts of fertilizer N applied are frequently more than the amounts removed by the crop. Excessive N application may result in short-term accumulation of nitrate nitrogen (NO3-N) in soil, which can easily be leached from the root zone and into the ground water. A management practice suggested for conserving accumulated NO3-N is the application of oily food waste (FOG; fat + oil + greases) to agricultural soils. A two-year field study (1995-1996 and 1996-1997) was conducted at Elora Research Center (43 degrees 38' N, 80 degrees W; 346 m above mean sea level), University of Guelph, Ontario, Canada to determine the effect of FOG application in fall and spring on soil NO3-N contents and apparent N immobilization-mineralization of soil N in the 0- to 60-cm soil layer. The experiment was planned under a randomized complete block design with four replications. An unamended control and a reference treatment [winter wheat (Triticum aestivum L.) cover crop] were included in the experiment to compare the effects of fall and spring treatment of oily food waste on soil NO3-N contents and apparent N immobilization-mineralization. Oily food waste application at 10 Mg ha(-1) in the fall decreased soil NO3-N by immobilization and conserved 47 to 56 kg NO3-N ha(-1), which would otherwise be subject to leaching. Nitrogen immobilized due to FOG application in the fall was subsequently remineralized by the time of fertilizer N sidedress, whereas no net mineralization was observed in spring-amended plots at the same time.     

Mutagenicity tests with gallic and tannic acid in the Salmonella/mammalian microsome assay

Gallic acid, tannic acid mixture and a purified fraction of tannic acid were evaluated for possible mutagenic activity in three strains of Salmonella typhimurium, TA98, TA100, and TA1535. These chemicals were not mutagenic either before or after activation with rat and woodchuck microsomal and cytosolic enzymes. However, tannic acid mixture and tannic acid fraction both gave a significantly (p = 0.05) dose-related reduction in the number of the revertant colonies, compared to the normal spontaneous revertants with no apparent toxic effects in the background lawn. With an agar diffusion assay, the chemicals exhibited toxic effects at 5000 micrograms/disc.     

Differential degradation of crude oil （Bonny Light） by four Pseudomonas strains

Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1–2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks (including aliphatics and aromatics) in the hydrocarbon mixture.     

Failure case studies of SA213-T22 steel tubes of boiler through computer simulations

Increased temperature and decreased hardness values of the tube metal and development of oxide scale on the inner surface of boiler tubes over prolonged period of time are typical problems in power plants. Appropriate life assessments or condition monitoring of boiler tube should be carried out from time to time. Computer simulations may economically support the post-failure assessment method, i.e. visual inspections, metallurgical examinations and mechanical strength measurements. However, estimations obtained from the simulations may provide an advanced warning to take preventive actions prior to failure. In this work two failure cases of the reheater and superheater tubes made of a typical material of SA213-T22 steel are evaluated. As the oxide scales are increasingly developed on the inner surface, the increasing of temperature and decreasing of hardness value in tube metal for both cases are determined. The remnant life estimations are then made in the form of creep cumulative damages.     

Equilibrium,kinetics and thermodynamics studies on adsorptive removal of cobalt ions from wastewater using MIL-100(Fe)

This study describes experiments in which MIL-100(Fe) was used to remove Co²⁺ ions from the waste water. The synthesised adsorbent was characterised by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, Brunauer–Emmett–Teller (BET) and scanning electron microscope. Statistical analysis was used to investigate the effects of different parameters. From the obtained results, the removal efficiency was enhanced with increasing contact time and pH but decreased with increasing cobalt initial concentration. The maximum removal efficiency of Co⁺² was 93.4% under optimum conditions. The equilibrium adsorption data were best fitted to linearly transformed Freundlich isotherm. Adsorption kinetic data followed the pseudo second-order kinetic model. The maximum adsorption capacity of Co⁺² on to the MIL-100(Fe) was found to be 119 mg g^?1. The results showed that ?G of adsorption was negative, while ?H was positive which showed that the adsorption process was spontaneous and endothermic. The positive value of ?S showed that disordering and randomness increased at the solid–solution interface of cobalt ions with MIL-100(Fe) particles.     

Sago pith waste ash as a potential raw material for ceramic and geopolymer fabrication

Journal of Material Cycles and Waste Management - This study focuses on the potential usage of sago pith waste ash (SPWA) obtained from sago pith waste (SPW) calcined from 500 to...